Such a stabilizer having a first and a second stabilizer member is known, for example, from DE 10 2009 001 907 A1. The stabilizer comprises, in addition to a locking flap which can be pivoted into a closed position in order to limit a resilient movement which occurs between the two stabilizer members, a pivotable curved securing member, by means of which a mutual rotation of the two stabilizer members and an associated adjustment of the total length of the stabilizer can be prevented. A recess formed in the locking flap enables operation of the curved securing member, even when the locking flap is in the closed position, which enables a lower link which is provided with the stabilizer to be twisted by hand when the mounted device is fitted. Since the stabilizer, as a result of its being fitted close to the ground, is subjected to comparatively high levels of contamination in the region of the lower link, particularly during field work, it is possible for this contamination to be deposited within the recess and for the operability of the curved securing member to be impaired in an undesirable manner.